The present invention relates to an electronic transaction method and system for electronically making a commercial transaction through a communication network, and particularly to an electronic transaction method and system capable of flexible electronic transaction by changing an electronic transaction process at each seller or financial institution or each element concerned with settlement such as merchandise to sell and an amount of money or at each combination thereof.
A remarkable electronic transaction system through a network is an electronic transaction system utilizing the Internet. This electronic transaction system, unlike the ones using the personal computer communications and CATV, has the advantage of being able to be used by everyone if connected to the Internet. In order to have electronic dealings through the Internet, it is necessary to provide a secure communications procedure capable of maintaining the secret of data in communication and a certifying procedure for confirming a person or company with which one has dealings.
Various different electronic transaction procedures have been developed for these necessaries. There are STT (secure transaction technology; executed by Microsoft and VISA), SEPP (secure electronic payment protocol; used by MasterCard, IBM, Netscape, CyberCash, and GTE Corp) and SET which are used for settlement of credits. These satisfy the above requirements by defining different data items in communication, coding/decoding systems, digital signature/certification procedure, and data checking method. Thus, the user can make secure electronic transaction on the Internet by executing applications software having these procedures utilized.
In addition, these electronic transaction procedures are being tried to be unified. One of the combined versions is Universal Payment Protocol (CyberCash). In this combined version, data contents are expressed in MIME form, and communication data items are automatically sent on an application of the described procedure. The Universal Payment Protocol is written in, for example, INTERNET-DRAFT, "Universal Payment Preamble", Nov. 6, 1995, pp. 2-15.
However, in order to use an application having STT, SEPP or SET incorporated, it is necessary to previously install it in the terminals for an electronic transaction. Thus, both seller and buyer must have the same application in order to make electronic transaction.
Also, since this application is now used only for the settlement of credits, transfer of money to a bank and settlement of electronic money will be required to use an application that has another electronic transaction procedure incorporated. In other words, the electronic transaction user needs various kinds of application soft for the respective electronic transaction procedures, which increase the capacity of the memory in the user's terminal.
Moreover, when there is a need to change the electronic transaction procedure, coding/decoding system, digital signature/certification procedure or data checking method in order to improve the service to the users, a new application after the change must be again distributed to the users. Therefore, it is not possible to flexibly and swiftly overcome the difficulties in the change of electronic transaction procedures.
Meanwhile, the Universal Payment Protocol can unify data communications, but still needs various different applications because received data are treated by each application for electronic transaction. This results in the increase of the capacity of the memory in the terminal of the electronic transaction user as described above.